Railway traffic controlling apparatus



Oct. 29. 1940. R. R. KEMMERER 5: AL. ,219,901

RAILWAY TRAFFIC CONTROLLING'APPARATUS Filed Sept. 15, 1958' 2 Sheets-Sheet 1 THEI R ATTORNEY Oct. 29. 194 R. R. KE-MMERER ET AL 2,219,901

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Sept. 15, 19:58 2 Sheets-Sheet 2 Q5 SESAME? I M Y fiwhwfik i E muua imwmam Q N. m H R 0 L4 T S m 5 Eu $1 m. E mm kw M Li d mm kmdwm mm 3 E mm 3 53 um R n M N Q N 5% m \N n m Nu m .5 n NW1 ESQ m Nu EM ER as mm? 7 HQ umm l Q. Q g rfiuig $513M mfi m um 3 w I fi f N. M; wlIaT L mm E mm: a I w or steady energy in Patented Oct 29, 1940 UNITED STATES RAILWAY TRAFFIC CONTROLLING APPARATUS Ralph R. Kemmerer,

Swissvale, Pa., and Howell N. Dixon, Hamlet, N. C'., assignors to The Union Switch & Signal Com pany, Swiss'vale, Pa., a corporation of Pennsylvania Application September 15, 1938, Serial No. 230,083

15 Claims.

Our invention relates to railway trafiic controlling apparatus and more specifically to apparatus for stopping the operation of highway crossing signals, operating detector locking track circuits, as well as forclearing out detector track sections generally in signalling systems employing circuit current, such as coded code following track relay which controls the usual wayside signals is not required to perform the clearing out operation for the highway crossing signals, the latter function being performed by other apparatus selectively responsive to the unccded energy which is provided for the purpose of signal clearing or track circuit detection. In this manner, the danger of improper signal operation due to an accidental failure of the code following track relay to operate is diminished and the safety factor of the system as a whole is increased.

We shall describe one form of railway traffic controlling apparatus embodying our invention and shall then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1a and 11) when placed end to end with Fig. 1b at the right highway a train.

Similar reference characters refer to similar parts in each of the two views.

In coded wayside and cab signalling systems which include the control of highway crossing apparatus or require the track detection functions it is desirable-that the current which is used for clearing out the highoperation can be obtained is by using coded current for the control of the wayside and cab signals and using uncoded or so-called steady energy for the control of the highway crossing or other detection apparatus. By making use of uncoded the rails, a distinctive response of certain auxiliary apparatus can be obtained which response can be used for the selective control of the highway crossing or other apparatus without at the same time causing an undesired response of the cab or Wayside signals. These, as is well known, will usually require the One advantage of coded wayside signalling systems over systems of gized track circuit type is provide a high degree of foreign current protection. Where steady energy is used for the clearthe usual steadily enercurrent protection may be lost thereby. Moreover, the design of the usual code following track relay is such that it is considered a safety type relay only when performing a code following or dynamic function in contrast with a steadily energized or static function in which its front contacts remain constantly closed.

Our apparatus disclosed herein is directed to overcoming the above track relay itself and which responds selectivel to the presence of steady energy in therails for.

cuit sections are necessary for the proper control of highway crossing apparatus at locations D wayside signal 8. Each track circuit is provided with a code foldisadvantages and we acg .35 proper operation of lowing track relay designated by the reference character TR with a sufiix corresponding to the location. As shown,'these code following relays are of the two-element alternating current type having a control element 3 energized from the track and a local 'gized. The energy received by these track relays is supplied from a suitable track transformer T element 5 which is locally enerthat the former systems highway crossing signals 6X and AEX in a the track relay TRC and having a located at the other end of the track circuit, the primary of which is energized from a source of alternating or other periodic curren not shown, having the terminals BX-CX. interposed be-- tween those of the supplied with energy over line wires are suitable insulating transformers IT. These insulating transformers are for posure of the line wires to high, tension linesand other 'lines paralleling the track so as to avoid undesired capacity and inductive interference from such lines.

As determined by the condition of traffic in advance of the blocks A-C and C--F, the source of current for the respective track transformers may be coded at a rate of either 180 or times per minute by suitable code transmitters CT at locations C and F. In the embodiment which is illustrated, these code transmitters are of the constantly operating type. Provision is also made for supplying steady or uncoded energy to the track circuits GT and ABT for the purpose of clearing out or stopping. the operation of the manner to be set forth in detail hereinafter. The highway crossing signals SK and AliX are controlled by suitable governing relays XRD and XRE, respectively. Since the control circuits which connect these relays with the usual control apparatus for operating the signals are well known, these circuits are not shown in the drawings in order to simplify thedisclosure.

The cut section location B is a starting point for the control of highway crossing signals 6X. Similarly, the signal location C is a starting point for the control of the highway crossing signals AGX. For the purpose of controlling these highway crossing signals, the track circuits BT and ABT are each provided with an auxiliary track relay ATRC and ATRD, respectively, the particular functions of which will be described in detail hereinafter. Since there are no further highway crossing locations in the block C-F beyond location E, the track circuit T is provided only with the usual code following track relay without a corresponding auxiliary track relay. Track circuits AT and AAT both receive coded energy from the signal location C and similarly, track circuits 6T, A6T, and BBT all receive coded energy from the signal location F. This coded energy is, of course, repeated over contacts of the track relay at the respective locations B, D, and E into the corresponding track circuits in the rear thereof. The uncoded energy for track circuits GT and ABT is, however, not repeated from locations in advance but is supplied locally at the locations D and E, respectively.

We shall first describe the operation of the individual apparatus at certain of the locations within the blocks A--C and C--F and shall then describe more fully the sequence of events as a train passes through the stretch A-F in which these two blocks are included.

Looking first at location C, the auxiliary track relay ATRC is an alternating current relay which may be of any suitable type but is preferably of the polarity responsive type. Since this relay is required to respond to steady energy only, it need not be of the code following design. As shown, the auxiliary track relay is of the two-element type having a control element 1 which is connected in multiple with the control element 3 of local element 9 which is energized locally from a suitable source of alternating current having thetermitrack transformers which are the purpose of reducing exnals BX-CX. It will tions of winding 9 of relay the relative instantaneous polarity of this element is opposite to that of the element 5 of track relay TRC whereas elements I and 3 are of like instantaneous polarity. With these connections, the auxiliary relay will respond only to current of opposite instantaneous polarity as compared with that to which the track relay TRC will respond. Accordingly, the coded energy which is supplied to the track relay TRC will drive the be notedthat the connecauxiliary relay against its backstop (at such time as local winding 9 is energized) to hold this relay in its deenergized position. Also, theuncoded energy of opposite instantaneous polarity which is supplied for operating the auxiliary relay will not produce a pick-up operation of the track relay TRC. Obviously, relays ATRC and TRC could be of the polarized direct current type and be operated from' direct current instead of alternating current track circuits. Moreover, the polarized feature of these relays can be dispensed with, if desired, provided that relay TRC' is of the code following type and relay ATRC is of the non-code following type, but when this is done the safety factor of the system will be reduced somewhat.

The decoding unit DUC is of the usual and well-known type and for this reason has not been shown in detail in order to simplify the disclo- This unit usually comprises a transformer which is supplied with direct current periodically reversed at code frequency so as to produce an alternating current output of corresponding frequency of the transformer which output, in turn, energizes the decoding relays HC and DC through suitable rectifiers forming a part of the decoding unit. To explain this operation more fully, when the track relay TRC is following code, it supplies this periodically reversed energization to the input circuit of the decoding unit DUC over its contacts Ill-l I and ill-I2 from a suitable source of direct current having the terminals B-C. The decoding relay DC is suitably tuned by means of reactance and capacity (not shown) in well-known manner whereby it will respond only when the track relay is following code, that is, when the decoding unit DUC is delivering an output of 180 code. The circuit of relay HC is untuned so that this relay will operate both when the received code is 180 and also when it is 80.

The code received by the track relay TRC will be 180 when the block in advance of location F is unoccupied and will be 80 when this advance block is occupied by a train. When either of the track circuits ABT or BBT is occupied, the track relayATRC will receive uncoded energy as will appear more fully hereinafter. It will be noted that the energy for the local element 9 of auxiliary relay ATRC is carried over a back contact l3 of the decoding relay HC so that when code is receivedin the track circuit ET, the auxiliary relay ATRC will not be subjected to a hammering action against its backstop, thus eliminating excessive wear due to this cause.

Looking next at location B, there are provided at this location two slow release repeating relays TPB and ATPB which-provide a check on the code following action of the track relay TRB. Relay TPB checks that the front contact I4-l5 of relay TRB is being periodically closed at codeclosed at code intervals and that relay TPB is in the secondary winding ATRC are such that iii) and prevent such the track relay should for any reason cease to follow cede.

operation of the crossing signals is obtained during the progress of the train through the section.

As previous pointed out, the track circuits in the block C-F receive alternating current from one or another of the contacts I80 and BB ated by the code transmitter CTF at location F,

depending upon traffic conditlons Contact I80 operates at the former frequency to transmit the clear or unoccupied code, whereas contact 80 operates at the latter frequency and transmits the caution codeto the track circuits of block C F. The particular code frequency transmitted is dependenttupon trafiic conditions in advance which, in turn, are reflected by the position of the decoding relays HF and DF.

In the particular embodiment which we have shown at location F, the decoding relay DF which the primary winding of track transformer 'ID overfront contacts 32 and 33 of relay A'IPE, front contacts-34 and 350i relay TPD, and front contacts 36-431 and 3940 of relay A'IfPD. It is are required for the tram has completely vacated seen, therefore, that each of the track circults 6T, A6T, and BtT receives'180 paratus at location F. I V In a similar manner, the track circuits AT and AQT receive codedenergy from the code-translocation C, the particular code and well-known manner which need not be deformer ITC but whether track circuit 3T will receive this code or not will depend upon Whether will close its front contacts 42 ply 80 code to the track transformer TB of track circuit "1T. Consequently, track relay TEA will follow 80 code and so will cause the signal' t to display the caution indication. v

The crossing control relay XRE is normally enand 43 so asto sup-- ergized over a circuit which includes the front now describe the contacts 52 and 53 of relay HC and theffrontcon tacts 54 and 55 of relay ATPD. Location C is therefore a starting point for the control of the highway crossing apparatus at location E. Accordingly, when the train enters track circuit GT and deenergizes track relay TRC and decoding relay HC, the release of the latter relay will open the front contacts 52 and 53 so as to deenergize the relay XRE. This relay, in turn, will close its back contact 56 so as to initiate the operation of the highway crossing signals ABX at location E.

When the train enters the track circuit AST, the track relay TED and relays TPD and ATPD will all become deenergized. The opening of front contacts 54 and 55 of relay ATPD willmaintain the relay XRE in its deenergized condition.

With the opening of, the front contacts 36-31 and 39-40 of relay ATPD, the coded energy which had previously been supplied to track transformer TD will now be discontinued. As soon asthe back contacts 36-38 and 39-4] of this relay become closed, however, uncoded energy of opposite instantaneous polarity will be fed to the primary of track transformer TD and, therefore, to the rails of track circuit 6T. Whereupon, assoon as the track circuit ET is vacated, the uncoded energy will cause the auxiliary relay ATRC to become energized, back contact l3 of relay HC being closed at this time to cause energy to be supplied to the local winding 9 of relay ATRC. As soon as auxiliary relay ATRC becomes energized, it will close its front contacts 51 and 58 and so will complete the energizing circuit for relay XRD, which, in turn, will discontinue the operation of the highway crossing signals 6X at location D. During the time that track 7 circuit 6T receives uncoded energy, the track relay TRC is maintained deenergized by being driven against its'backstop so continues to remain at stop.

When the train enters the track circuit BET, the track relay TRE and its associated repeater relays TPE and ATPE will all become deenergized and uncoded energy will be fed to the track circuit ABT in the rear over the back contacts 25-30 and 28-3! of relay ATPE. When the track circuit AS'I becomes completely vacated, the auxil-.

'iary track relay ATRD will become energized on steady energy and in so doing will close its'front contacts 59 and 60, thereby closing the energizing circuit for the highway crossing control relay XRE. This relay will, in turn, open its back contact 56 to thereby discontinue the operation of the highway crossing signals ABX at location E.

When the track circuit BET is vacated, 80 code will be fed to this track circuit over the back contact 3-20 of decoding relay HF and wires 2| and 22 totrack transformer TF, as before. This code will also be supplied to track transformers TE and TD over the line circuits in the manner previously explained in connection with the supply of 180 code. Accordingly, relay TRC at location C will follow 80 code and will cause the signal to display a caution indication. In consequence, 180 code will be supplied over front contact 49-50 of relay 1-10 to track 3 transformers TC and TB. The response of relay TRA to 180 code will, of course, cause signal 4 to assume its proceed position.

When the train proceeds out of the block immediately in advance of location F, 80 code will be supplied to the track relay TRF which, in'following this code, will cause 180 code to be supplied to the track circuits of the blocks A-C and that signal 6 track relay receiving energy trol functions. The apparatus is further so arranged that the use of uncoded energy does not interfere with the proper safety operation of the usual code following track relay and does not decrease the foreign current protection provided by this relay.

Although we have herein shown and described only one form of apparatus embodying our invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our invention.

Having thus described our invention, what we claim is:

1. In combination with a section of railway track, means for at times supplying coded current and for at other times supplying uncoded current to the rails of said section, a code following track relay receiving energy from the rails of said section, an auxiliary track relay controlled by energy received from the track rails and designed for operation on said uncoded current but not on said coded current, a trafllc controlling line circuit, means controlled by said code following track relay effective at such times for maintaining said line circuit energized and for insuring non-operation of said auxiliary relay once code following action of said code following relay has been established, and means controlled by said auxiliary track relay effective at said other times for maintaining said line circuit energized in response to code operation of said code following track relay, means controlled by said decoding relay for insuring non-operation of said auxiliary relay once code following action of said code following relay has been established, a trafflG controlling line circuit, a front contact of said decoding relay included at said times in said line circuit, and a path around said front contact closed at said other times and including a front contact of said a 'liary track relay.

3. In combination with a section of railway track, means for at times supplying coded current and for at other times supplying uncoded current to the rails of said section, a code following from the rails of said section, an auxiliary track relay controlled by energy received from the track rails and designed for operation on said uncoded current but rails of said section and having a local element,

.a decoding relay energized in response to code operation of said code following track relay, means controlled by said decoding relay effective .at said other times for supplying uncoded current to the local element of to cause operation thereof,

repeating relay energized only in response to code operation of said code, following track relay, said repeating relay when energized being effective for track relay, and means controlled by said repeating relay when deenergized for supplying uncoded current to the rails in the rear of said track section. I

operation of said code following track relay, repeating relay is energized and including said and said auxiliary track relay. V

6. In combination with a forward and a rear section of railway track, coding means for at times supplying-coded current to the rails of said rent, means controlled means effective when) said nalling apparatus controlled by said auxiliary trackrelay.

ward section, a code following track relay for said forward section, a decoding relay energized only in response to code operation of said code following track relay, means effective when said decoding relay is energized for supplying coded.

current to the rails of said rears'ection to control traflic entering said rear section, an auxiliary track relay for said forward section controlled by energy received from the track rails and'designed for operation on said uncoded current, said decoding relay when energized being effective for preventing operation of said auxiliary track relay at said times when coded current is supplied to the rails of said forward section, and track detection apparatus controlled by saiddecoding relay and said auxiliary track relay.-

rent, said repeating relay for the forwardsection when energized being ei ective for preventing operation of said auxiliary times when coded current is supplied to the rails of said forward section, and tramc controlling apparatus governed by both said repeating relays and saidauxiliary track relay.

9. In combination with a forward and a rear auxiliary track relay. I

10. In combination with a forward and a reartrac]; relay at said the forward section for energizing said auxiliary track relay on said uncoded current as soon as the train vacates the forward section, means controlled by the codefollowing track relay for said forward section effective when this relay is operating for preventing hammering action of said auxiliary trackrelay against its backstop when coded current is effective in the rails of the ward section, and means controlled by said auxiliary track relay when energized for restoring said signalling apparatus to its normally inoperned by said main erative condition.

' 11. In combination with a section of railway track, means for attimes supplying coded current of a given relative polarity and for at other times supplying uncoded current of the reverse relative polarity to the rails of said section, a main track relay responsive tocode and receiving energy from the rails of said section, a two-element auxiliary track relay having its control element energized from the railsj'of said section, means controlled by said main track-relay for preventing energization of the local element of said auxiliary relay at said times once code following action of said main relay has been established, means effective at said other times for energizing said local element to cause pick-up of said auxiliary relay on said uncoded current, the energization of said local element being in such direction as to prevent pick-up of the auxiliary relay on code during the time required for the code following action of said main relay to be established, trafiic controlling apparatus govtrack relay, and track detection apparatus governed by said auxiliary track relay.

: said auxiliary relay l2.-In combination with a section of railway track, means for at times supplying coded current of a given relative polarity and for at other times supplying uncoded current of the reverse relative polarity to the rails 'of said section, a main track. relay responsive to code and receivingenergy from the rails of said section, a twoelement auxiliary track relay having element energized from the rails of said section, means controlled by said main track relayfor preventing energization of the local element of at said times once codefollowing action of said main relay has been established, means effective at said other times'for energizing said local element to cause pick-up of said auxiliary relay on said uncoded current, the energization of said local element being in such direction as to prevent pick-up of the auxiliary relay on code during the time required for the code following action of said main relay to be established, and traflic controlling apparatus governed by said main track relay and said auxiliary track relay.

13.'In combination with a section of railway track,'means for at times supplying coded current of a given relative polarity and for at other lowing action of said main relay for-- its control times supplying uncoded current of the reverse relative polarity to the rails of said section, a main track relay responsive to codeand receiving energy from the rails of said section, a two-element auxiliary track relay having its control element energized from the rails of said section, means controlled by said main track relay for preventing energization of the local element of said auxiliary relay at said times once code folhas been established,- means effective at said other times for energizing said local element to cause pick-up of said auxiliary relay on said uncoded current, the energization of said local element being in such direction as to prevent pick-up of the auxiliary relay on code during the time required for the code following action of said main relay to be established, and a traffic controlling line circuit governed by said main track relay and said auxiliary track relay.

14. In combination with a section of railway track, means for at times supplying coded current and for at other times supplying uncoded current to the rails of said section, a main track relay responsive to code and receiving energy to prevent pick-up of the auxiliary relay on code during the time required for the code following action of said main relay to be established, a highway crossing control relay, a first circuit for said highway crossing control relay governed by said main track relay, and a second circuit for said highway crossing control relay governed by I said auxiliary track relay.

15. In combination with a forward and a rear sectionof railway track, means for normally supplying coded current to the rails of both sections, a main track relay for said rear section responsive to code, means effective when a train enters said forward section for supplying uncoded current of reverse relative polarity with respect to said coded current to the rails of said rear section, a two-element auxiliary track relay having its control element energized from the rails of said rear section, means controlled by said main track relay for preventing energization of the local element of said auxiliary relay when code is supplied to the rails of said rear section once code following action of said main relay has been established means effective when imcoded current is supplied to said rear section for energizing said local, element to' cause pick-up of said auxiliary relay on said uncoded current, the energization of said local element being insuch direction as to prevent pick-up of the auxiliary relay on code during the time requiredfor the code following action of said main relay to be estab lished, \train governing apparatus controlled by said main track relay, and track detection apparatus controlled by said auxiliary track relay.

RALPH R. KEMMERER. HOWELL N. DIXON. 

